Sway bars are used to stabilize the body of a motor vehicle or the like. For example, sway bars are used to prevent side sway caused by the inertia of a vehicle, as in going around a curve. In order for it to properly perform this function, it is important that the sway bar be made out of high strength steel having a high modulus of elasticity, i.e., stiffness.
Steel sway bars have heretofore been formed by hot forging steel blanks into the desired shape. Hot forging techniques are well known in the art. In typical hot forging, the steel blank used to make the sway bar is initially heated well above the recrystallization temperature of the steel to about 2,000.degree. F. and higher. While at this temperature, the steel blank is forged into a sway bar. Once the final shape of the sway bar has been obtained, the mechanical properties of the finished sway bar are produced either by subsequent normalizing or a quench and temper procedure, depending on the steel being used and the final mechanical properties desired. Hot forging a steel blank to the final shape produces a steel having grains with a random orientation.
In addition, at the temperature reached during hot forging, substantial scale and decarburization of the steel may occur. Since the scale and decarburized surfaces must be removed to obtain the finished part, some known hot forging techniques result in the waste of a certain amount of material and result in increased costs due to the additional processing steps required to remove the scale. Furthermore, hot forging is costly due to the energy consumed in heating the steel blank to the forging temperature. The manufacturing costs grow even higher when quench and temper steps are performed due to the increased energy consumption during austenitizing and tempering as well as the costs associated with having additional processing steps.